using System;
using ArchestrA;
using ZB.MOM.WW.LmxOpcUa.Host.Configuration;
using ZB.MOM.WW.LmxOpcUa.Host.Historian;

namespace ZB.MOM.WW.LmxOpcUa.Tests.Helpers
{
    /// <summary>
    ///     Fake Historian connection factory for tests. Controls whether connections
    ///     succeed, fail, or timeout without requiring the real Historian SDK runtime.
    /// </summary>
    internal sealed class FakeHistorianConnectionFactory : IHistorianConnectionFactory
    {
        /// <summary>
        ///     When set, <see cref="CreateAndConnect"/> throws this exception.
        /// </summary>
        public Exception? ConnectException { get; set; }

        /// <summary>
        ///     Number of times <see cref="CreateAndConnect"/> has been called.
        /// </summary>
        public int ConnectCallCount { get; private set; }

        /// <summary>
        ///     When set, called on each <see cref="CreateAndConnect"/> to determine behavior.
        ///     Receives the call count (1-based). Return null to succeed, or throw to fail.
        /// </summary>
        public Action<int>? OnConnect { get; set; }

        public HistorianAccess CreateAndConnect(HistorianConfiguration config, HistorianConnectionType type)
        {
            ConnectCallCount++;

            if (OnConnect != null)
            {
                OnConnect(ConnectCallCount);
            }
            else if (ConnectException != null)
            {
                throw ConnectException;
            }

            // Return a HistorianAccess that is not actually connected.
            // ReadRawAsync etc. will fail when they try to use it, which exercises
            // the HandleConnectionError → reconnect path.
            return new HistorianAccess();
        }
    }
}